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CHRISTINE ROMANS, CNN ANCHOR: Breaking news this morning. The dramatic change in the search for missing Malaysia Airlines Flight 370. Australia is now the country taking the lead and using new technology in and under the water to narrow the search field and to find that vanished jetliner's flight data recorder. Time is running out.

We have live, team coverage, covering everything you've missed, every development overnight.

POPPY HARLOW, CNN ANCHOR: Also, new information this morning on the soldier behind a deadly massacre at Fort Hood. What could have provoked that attack and how soldiers injured in the shooting, how are they doing. We've got a live update on the victims, straight ahead.

ROMANS: Breaking news this morning on a powerful storm system that tore through the Midwest. It's heading east. Tornadoes, floods, even snow, everything you need to know about what's happening right now. Indra Petersons is tracking this dangerous weather for us.

A potentially significant shift in the search for missing Flight 370. The focus now under water with the U.S. Navy's pinger locator and other high-tech acoustic gear trying to detect transmissions from the plane's missing black box.

Australian officials who have now taken the lead are now tracking an area where they say the plane is most likely to have gone down in the Southern Indian Ocean. Nearly two dozen ships and aircraft also taking part in this search.

Let's go straight to Matthew Chance. He is live in Perth, Australia for us this morning.

It is that hour of the day when those search planes return from their hours of scouring this vast area. Have they come up with anything?

MATTHEW CHANCE, CNN SENIOR INTERNATIONAL CORRESPONDENT: No. In fact, we haven't heard any of them yet have got back from today's mission to scour that vast area, 85,000 square miles, which is about 1,000 miles off the coast of western Australia, remember. So it's a long time to get there, a long time to get back as well. And so it's a huge day that they've had behind them and they haven't yet got back.

And so, obviously, we'll try and bring you some more details if any more come down to us. But you're right, the emphasis of the search, or at least the new phase in the search has begun today. It's moved from the skies under the surface of the ocean with the arrival of a number of assets that are key in order to try and detect the pinger on the black box that was on the Malaysian airliner.

Two vessels in particular. An Australian vessel called the Ocean Shield, which has that U.S. pinger detector on the back of it being towed at the back. A British vessel has a similar bit of technology. There's also a British nuclear submarine in the area engaged in the search as well. So they've got those assets there and they're using them as best they can before time runs out, because that's a real pressure as well.

These battery lives on these pingers are said to last somewhere in the region of 30 days. It's been 28 days already, and so their concerns are growing that the battery could -- you know, could run out and the pings will not be emitted anymore, making this technology useless. And so they're using it while they can in an area which they say has the highest probability of the plane being located.

Take a listen to what Angus Houston, the head of the Australian search mission and the coordinating office here, had to say about it earlier.

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ANGUS GRANT HOUSTON, JOINT AGENCY COORDINATION CENTRE AIR CHIEF MARSHAL: We have not searched everywhere where the aircraft might have gone. I mean, we are concentrating in an area that has been developed as a consequence of the analysis.

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CHANCE: So he's concentrating in that area, the area where he says is the highest probability of the plane being found on the basis of the data that they've recently found, but he warned that it is a vast area, it's a remote area. And after 28 days, Poppy, they still haven't found a trace of that missing airliner.

HARLOW: That is what is just so incredible, and understandably hard for the families, especially, left behind to believe the Malaysian prime minister, who just left Perth after a two-day visit, saying, "I can promise them that we will not give up". The search continues.

Matthew Chance, thank you.

ROMANS: The subsurface search has renewed hope on day 28 that Flight 370 might yet be found, but the window to locate the black box, of course, closing fast. Perhaps only a day, or maybe two of battery life left in those black box pingers. CNN's Will Ripley joins us live. He's on a boat off the coast of western Australia, and he's going to give us kind of -- I don't know, walk us through what the weather conditions are like. We have two searches here. We have a search on the water and a search below the water in a part of the ocean that's much more forgiving than some of the earlier search zones in the far south Indian Ocean.

Walk us through what you're seeing there -- Will.

WILL RIPLEY, CNN CORRESPONDENT: Yes, that was certainly a promising development in the sense of, yes, Christine, the weather is better in this new search area than it was when it was farther to the south, when it was really pretty treacherous.

Out here, we're monitoring, we're getting updates from the Australian Defense Force. And while the search zone is about 1,000 miles from this area that we're showing you live right now, we're told the weather conditions there are very similar to what we're seeing here, relatively smooth seas, not very many white caps, which means it's relatively easy to see debris that may be floating on the water.

So you know, when you have -- when you have more rough surf, the problem is, is it's very difficult visually to get -- to get a good look at what may or may not be there. And the weather also affects the underwater search as well, because when you have clear conditions like this, the pinger locator that's being towed behind the Australian ship, the Ocean Shield, it can listen for longer.

When you have rough currents, it actually affects the sonar technology. You know, there's a British ship with this side-scanning sonar, so it's scanning all around the entire ship for anything, any debris, any objects that may be nearby. And so when you have relatively clear conditions like this, it allows all of this technology to work much more effectively.

So we're hoping that this weather will continue like this for the coming days, although it's so unpredictable, as we've seen time and time again.

ROMANS: Yes, it sure is. Will Ripley, thank you so much, off the coast of western Australia. Thanks.

Much more ahead on the search for that flight, the latest on the missing plane investigation with our Jim Clancy in Malaysia and the families, their agonizing wait goes on.

HARLOW: Also now to the shooting rampage at Fort Hood, Texas, the second mass killing there in five years. Investigators just trying to piece together why Army Specialist Ivan Lopez opened fire, killing three people, wounding 16 others before taking his own life.

As we learn more about the shooter, a picture is emerging of a troubled, mentally unstable soldier.

Our George Howell is reporting live from Fort Hood this morning. And George, you know, it's interesting. You've been saying to us that this is not the picture of him that anyone that seems to have known him there on the base had.

GEORGE HOWELL, CNN CORRESPONDENT: Right, fellow soldiers, they say this was out of character. They describe him as a person, you know, who had a lot of values, an extraordinary individual. All of it, they say, out of character. But when you look at what happened the other day, you do have to look into the background of mental illness. That's what investigators are doing as they try to understand the motive, the reason behind the shooting.

We do know that they will be looking at an altercation, a verbal altercation that took place prior to the shooting that could have played factor. They're also looking into his history of mental illness, looking into the variety of the medications that he was taking. He was taking the drug Ambien, a sleep medication, also taking antidepressants, and he was being evaluated for PTSD, for post- traumatic stress disorder, though he was not officially diagnosed with PTSD.

Want you to know, though, investigators say they are looking at all angles in this to try to understand why this happened. Take a look.

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LT. GEN. MARK MILLEY, COMMANDER, FORT HOOD: At this point, we have not yet ruled out anything whatsoever, and we are committed to letting the investigation run its course, but we have, again, no indications at this time of any links to terrorist organizations of any type, either national or international.

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HOWELL: Three people were killed in this shooting, 16 injured. Of the 16, three were in critical condition, but we have learned that those three have been upgraded to serious condition this morning.

HARLOW: I was just going to ask you how the victims are doing. And on that point, do we know, George, whether or not Lopez knew at all any of those that he killed or any of those that he wounded? Do we have any idea whether there was any sort of specific target here?

HOWELL: Well, you know, investigators, obviously, will be looking into all angles. But so far at this point, and I would venture to say, it's still very early in the investigation, but they say that they don't believe that he was targeting anyone specifically. Still, we know that it happened between two buildings, between the medical building, between the transportation building.

We know that, you know, perhaps he may have known soldiers, but was he specifically targeting these soldiers, still unclear.

HARLOW: Right. And that is such a big base. I mean, some describe it as a small city in and of itself. It has tens of thousands of soldiers on it. So many questions still to be answered, but we do know he got that gun legally, but it was not registered on base.

Thank you for the reporting this morning, George. Appreciate it.

ROMANS: They're trying to piece it all together. You know, the commanding general of Fort Hood said yesterday that, "We believe that his mental health history is the fundamental causal factor," saying his mental history indicates unstable psychiatric and psychological conditions.

At least a month ago he had been seen for that, he had been prescribed a bunch of different medications. They'll try to piece that all together, who he was, who his friends thought he was, what his history was on the base and then put that together.

You know, the death of his mother apparently, Poppy, hit him pretty hard.

HARLOW: Yes.

ROMANS: He was reportedly upset that the army only gave him, you know, a couple of days, less than two days leave to attend her funeral. And you know, some people who knew him, especially his army brethren, say they didn't see a hint of what was to come.

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SGT. MAJOR NELSON BIGAS, PUERTO RICO NATIONAL GUARD: He was one of my best soldiers in the organization. And he has the dynamic leadership. Specialist Lopez was an outstanding soldier with great initiative. He showed great leadership and a very great military discipline.

JOHN MCHUGH, ARMY SECRETARY: He was seen just last month by a psychiatrist. He was fully examined. And as of this morning, we had no indication on the record of that examination that there was any sign of likely violence, either to himself or to others, no suicidal ideation.

BRADLEY: He seemed pretty fine, happy. He didn't seem like, you know, the type that would do what he did.

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HARLOW: Well, Army Sergeant Timothy Owens, you see him right there, he was one of those killed at Fort Hood. He was from Illinois. His family there spoke with our affiliate WICS.

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MARY MUNTEAN, MOTHER OF SGT. TIMOTHY OWENS: He didn't answer the phone. So I left a message on his phone. Son, call me so I know if you're OK or not. Well, never got no call from him. I thought, oh, god, please don't let it be.

WALLACE GERHARDT, UNCLE OF SGT. TIMOTHY OWENS: He was just a very honorable, you know, individual. And like I say, I don't think he knew any strangers. Everybody that he met, I believe, that Tim got along with them.

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ROMANS: Hearts go out to them, really. And you're supposed to be safe. That's one place you're really supposed to be safe.

HARLOW: You're right. You're right.

ROMANS: All right. Breaking news overnight, trees ripped from the ground, homes destroyed, communities under water. Millions, millions of you feeling the wrath of this vast storm system, and it's not over yet.

Indra Petersons tracking it all for us next.

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ROMANS: All right, happy Friday. And millions of you are in the path of some severe weather. Be careful out there. Hitting the Midwest, hitting the south. Tornadoes, heavy rain, damaging hail.

Here's what happened. As many as eight twisters reported across several states yesterday.

HARLOW: Tornadoes reported in several Missouri counties. The St. Louis suburb of University City cleaning up from a twister that struck there nearly 24 hours ago. Big trees, no match for the strong winds. A number of homes actually had their roofs ripped off. The storm knocking out power for thousands of folks there.

ROMANS: Missouri's governor declared a state of emergency. The band of severe weather moving across that state. You can see the funnel clouds forming over the sky in Kansas City, and torrential rain caused significant flooding along the Missouri/Kansas border.

HARLOW: And parts of Texas getting clobbered by this severe weather as well. That included reports of tornadoes there. Look at that. Some hail, even golf ball-sized hail. The town of Denton, about 40 miles from Dallas-Ft. Worth, saw two rounds of big hail just about two hours apart.

ROMANS: Indra Petersons tracking this for us, and she's here to tell us it's not necessarily in the rearview mirror. I see the red and yellow boxes on your screen.

INDRA PETERSONS, AMS METEOROLOGIST: Yes, not even close. Unfortunately we have a whole another day of severe weather that still with us. And we do currently still have not only severe thunderstorm watches, but tornado watches where you see those red boxes. We still have tornado watches, so heads up, especially if you're out there in Tennessee, Mississippi, Alabama, Louisiana, even back through Texas.

That squall line is making its way through your region currently. What are we looking at? That threat for even tornadoes should be for 20 million of you today. The slight risk itself going from Charleston all the way back through Naches, especially in the afternoon. Even as you start to see things calm down a little bit typically in the afternoon, you get more sunlight and you start to see the systems fire up again, and that means that danger is out there.

Just one look at what we saw yesterday, eight tornadoes. I mean, Texas, looks like Missouri, even in through Illinois reported tornadoes yesterday. Many reports of wind as damaging in many places with straight-line winds as tornadoes. The other side of it was the heavy rain, very heavy rain in short periods of time brought flooding concerns, four, five inches out there. All of this still making its way to the northeast today, diminishing the threat, but you definitely need to stay aware.

HARLOW: Yes. Absolutely.

ROMANS: Stay aware.

HARLOW: Thanks for the update. Appreciate it, Indra.

All right. Let's take a look at what's coming up on "NEW DAY" this Friday. Chris Cuomo joins us now.

What's ahead?

ROMANS: Hey, Chris.

CHRIS CUOMO, CNN ANCHOR, NEW DAY: Ladies, happy Friday.

ROMANS: Happy Friday.

CUOMO: Of course we're following the latest breaking information in the search for Flight 370. A little confusing. It sounds like there's been a good advancement here. They're now using the underwater pinger locators. Those have to be fairly close in proximity to the black boxes in order to detect them. So does that mean they've found this proximity? Maybe. Maybe not.

They're actually searching a very big area, like 150 square miles. So we're going to talk to an officer who's in charge of the U.S. pinger locator and our aviation experts will weigh in about whether or not this is an indication that they're getting closer, or is this just what they're trying right now.

Plus, we're going to get very deep into Fort Hood shooting. Why? Well, we have new details about the gunman and his mental health and the role that his treatment may have played, the role treatment may have played in what happened. So we'll take you through that in the specific.

But also, we're going to talk to a soldier who survived the 2009 massacre, to let us know what it was like to be in that moment of trauma. Remember, there's still victims who are dealing with what happened there, fighting for their lives in the hospital. We'll take you through that.

Also, we're going to get into the bigger issue, the bigger issue here, Christine and Poppy. It is, what do we do about mental health in this country?

HARLOW: Right.

ROMANS: You are so right.

CUOMO: Not enough say the experts.

ROMANS: You are so right.

CUOMO: Representative Tim Murphy has a big bill. It's been suffering from some politics, political lag.

HARLOW: Right.

CUOMO: The timing, the event, the hearing was yesterday. He's on the show today. His main forensic expert is on the show today to tell us why they believe now is the time to change.

HARLOW: We will be looking forward to that and watching. Thank you, Chris. Appreciate it. We'll see you on "NEW DAY" in just a few minutes.

Folks, we'll be right back.

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ROMANS: Australian officials have taken the lead in the search now for flight 370, and an underwater search has gun with a high-tech pinger locator, listening for any communication from the black box, from those data recorders, but still no trace, no trace yet of 370. Time running out. Battery life in the black box may only have another day or two.

So we know that the families wanted to hear that final voice communication from the cockpit, and investigators say no. We also know, Jim, wow, these investigators -- Malaysia is under intense pressure. How are they weathering this? I mean, there's been criticism from the Chinese, from the families. Bring us up to speed on that part of the story.

JIM CLANCY, CNN INTERNATIONAL CORRESPONDENT: It's very obvious that the lack of details, the lack of information about this story has led to charges, mostly on the Internet, springing up from China, saying that the government of Malaysia is involved in a cover-up. Malaysian officials say, no, no, we're not. But according to a political science professor here, the problem is that Malaysia doesn't really have a strategy to deal with that. Listen.

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JAMES CHIN, MONASH UNIVERSITY: Hoping to ride out the storm. But key to all this issue that you must locate the plane first. Because once you have certainty about what happened, a lot of this chattering you find on cyberspace will die off.

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CLANCY: All right, when you look at that, you see what the problem is. All of their hopes pinned on what is happening this day, tomorrow in Australia, finding some trace of Flight 370.

Back to you and EARLY START.

ROMANS: Thank you. Thank you so much, Jim Clancy, in Kuala Lumpur.

HARLOW: And we'll be right back with more news straight ahead.

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ROMANS: Welcome back. European stocks right now up slightly, but the story today, the only story is something that hasn't happened yet. That's right, the March jobs report from the Labor Department.

Here's what economists expect. They expect a spring thaw in those March numbers. 213,000 net new jobs added last month, that's their forecast. Stronger than February. Their forecast for the jobless rate, 6.6 percent. Still digging out of the hole that was built by the recession, no question, but look at this chart. It's the total number of jobs in the country. And you can see how close we are to getting back to the number of jobs we had in 2008.

If more than 129,000 jobs are created in March, it means the private sector will have made up all of the lost jobs in the recession in the crash that followed. The key word here is private, private-sector jobs. Uncle Sam still lagging behind in job creation, but that could be -- today could mark the day where we're back to where we started.

HARLOW: We could. That number coming live, 8:30 Eastern. You're going to see Christine with it live on "NEW DAY," which by the way begins right now. Have a great weekend.